1. Field of the Invention
The present invention relates to a novel tape cassette, and, more particularly, to an improvement in the structure of a tape cassette in which step portions formed on the side surface portions of the tape cassette can be made small and also a smooth opening/closing operation of the front lid can be performed.
2. Description of the Related Art
In connection with the enhancement of the recording density in a tape cassette field, there has been developed and known such a technique that a part of a tape-shaped recording medium exposed from a cassette shell to the outside is covered by a cover member called a xe2x80x9clidxe2x80x9d when a tape cassette is not used, thereby preventing dusts, oil and other foreign matter from adhering to the exposed part of the tape-shaped recording medium.
In such a tape cassette in which a tape-shaped recording medium located so as to pass through the front side of a mouth portion that is provided to the front portion of a cassette shell and opened in forward and up-and-down directions is covered by a front lid at the front side thereof and the tape-shaped recording medium is exposed to the outside by rotating the front lid upwardly by substantially 90 degrees when the tape cassette is used, members to be arranged in the mouth portion suffer various restrictions when the tape cassette is used because the upper side of the mouth portion is closed by the front lid. Therefore, as a technique of solving this problem, a slider is equipped to the cassette shell so as to be freely movable forwardly and backwardly, the front lid is freely-rotatably mounted to the front-end portions of the slider, and the front lid is upwardly swung while the slider is backwardly moved when the lid is opened, thereby preventing the front lid from stopping at the upper side the mouth portion (see FIG. 26).
In such a case where a slider a is merely equipped to a cassette shell b so as to be freely movable forwardly and backwardly and the front lid c is merely freely-rotatably fixed to the front end portions of the slider a when the front lid is mounted on the slider, when the tape cassette d is required to be designed so that the distance between the front-end portions thereof is equal to the distance between the rear-end portions, that is, the lateral (exe2x80x94e) width of the front lid c is set to be equal to the lateral width (fxe2x80x94f) of the rear face of the cassette shell b, a large step g occurs between each rear-end portion f of the cassette shell b and each slide surface portion of the cassette shell b along which the slider a is slid because each outer-side surface of the slider a is located farther inwardly than the side-surface portion e of the front lid c by an amount corresponding to at least the thickness of the side surface portion e of the front lid c.
When the tape cassette d thus constructed is inserted into a holder h to mount the tape cassetted at a predetermined mount position of a recording/reproducing apparatus, there would occur such an accident that step g is unintentionally hooked to a corner of the cassette entrance of the holder h or the like if the insertion orientation of the tape cassette is slightly inclined or the like (see FIG. 26).
Therefore, the present invention has an object to make small the steps of the side-surface portions of the tape cassette (i.e., reduce the height of the steps) and, also, to enable the opening/closing operation of the front lid to be smoothly carried out.
In order to solve the above problem, according to the tape cassette of the present invention, a slider is provided so as to be freely movable forwardly and downwardly; each side surface portion of the slider along the side surface of the front lid has a lid-support portion at the front-end portion thereof and a main-surface portion located outside of the lid-support portion; the front-lid has a front-surface portion covering the front surface of the tape-shaped recording medium and side-surface portions projecting backwardly from both the ends of the front-surface portion, the side surface portions being freely rotatably supported to the lid-support portion of the slider; and the front-end portions of the slider and the side-surface portions of the front lid have overlap portions which are overlapped with each other in the right-and-left direction.
Accordingly, in the tape cassette of the present invention, the main surface portions of the slider are located so as to be farther outwardly projected than the lid support portions thereof, and thus the corresponding slide portions of the side surfaces of the cassette shell along which the main surface portions of the slider are slid are located so as to be farther outwardly projected than those of the prior art. Therefore, the step occurring between each rear-end portion and each slide portion can be reduced. Further, the overlap portions are provided to the front-end portions of the main-surface portions of the slider and the side-surface portions of the front lid so as to be overlapped with each other in the right-and-left direction, Therefore, the overlap portions of the front lid are guided by the overlap portions of the slider during rotation of the front lid, so that the opening/closing operation of the front lid is smoothly carried out.